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In view of the close relationship of deserpidine with 3-epi-a-yohimbine73'8 the former appeared to have an epialloyohimbane skeleton, whose D/E ring juncture was unambiguously cis, as suggested by Janot's conversion of sempervirine (Ha) to d,/-alloyohimbane (Ilia) by catalytic hydrogena-tion9 and corroborated by stereospecific syntheses of d,/-epialloyohimbane (Ilia) and its diastereomers.1011 However the configuration at C-3 was by no means as clear. The sempervirine reduc-tion9 unfortunately was of little diagnostic value on this point because of the uncertainty of the stereochemistry of catalytic hydrogenation in alkaline medium, and became less so when it was discovered that a large-scale reduction led not only to the alio compound but also to some d,lepialloyohimbane.ld Whereas the production of the alio derivative by hydrogenation of d,l-A3alloyohimbene in the last step of a total synthesis103 suggested a syn-cis configuration (IVa) for allo-

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